I just dropped my intake off at the powder coater.
We had a discussion of which parts to mask off and I'm not sure what is right?
He adviced not to paint the surface under the intake facing the gasket
Any advice here would be appreciated.

Cheers/Peter

 

Was it coated before? I haven't taken mine off so I don't know. If so, the coating method he uses may not to stand up to the heat/pressure and he's just being honest with you. If it wasn't coated before, I wouldn't coat it now.

I'd imagine if the coating starts to crack under there it would cause all kinds of vacuum leaks. Mine whistles like crazy, but I'm not taking care of that until I can powder coat and replace all of the gaskets.

Enjoy the new look!

Let us see what she looks like when it's finished.

 

I don't have the same intake, but mine was masked over. All of the powder coating I've seen has a rough texture so you wounldn't want that between the intake & gasket.

 

ON my 1988 intake I did same thing as Porsche did: powder coat gasket area, injector seating area, etc.

 

ditto

 

Mask the gasket surface. Heat is not an issue because your engine will not reach 400 degrees and if it does you will need to worry about more than the coating. Make sure he strips all of the factory coating or it will bubble up under the powder.

 

Hi,

I am doing my 86 right now... so I am in the same boat... Of course the old flakey stuff has to be removed... powder coating works like metal plating... by placing an electrode on the part and charging it... they will use a high temp tape for flat surfaces and some silicone based material to plug the thread holes... The parts are usually stripped chemically, blasted, and then baked to burn off any residues... Blasting should be with glass or some say nut shells??? I guess the magnesium alloy is a bit brittle and pourous... so harsher balsting can remove too much material...

I saw a really nice powder coat done on a later intake... (outsourced by one of the big three) The coat was taken all the way to the gasket surface of the cam covers... but not inside the cam cover.... I don't remember if the intake gasket surface was done... but the inside of the intake tubes was done... the intake gasket surface on our 85-86 cars was haly painted/coated from the factory...??? Not sure if powder coating was a common technology in the mod 80's... it was pretty new when it cam in vogue for bicycles in the late 80s...

I am taking mine in this morning... I was considering just having them stripped and leaving the inside the raw mag alloy... I wonderif that is a mistake... The mag alloy does oxidize quickly but I imagine that with the oil vapour in the intake that the surface will be fine... I am more worried about loose pwder coat or my stock paint or whatever it is comiing off and getting into the combustion chamber.

Oh yeah be sure that your pweder coat guy know that he must blast and then proceed fairly quicky because the surface oxidation....

LO

 

I prefer ceramic coating versus powder coating. The coating is so thin and durable that most folks just have the entire thing coated, including any threaded orifices such as for the top holddown bolt and the banjo fitting for the trans vacuum.

Powder coating tends to be thicker, but the gasket surfaces should be OK to coat, but threaded openings should be taped off.

 

Ok,

it will be done like he suggested and I will get it back on Wednesday next week.
It is really exiting to see how this will come out
The colour chosen is dark blue base coat with some special lasyr blue on top and finished with a clear coat.
If it turns out the way I think it will compliment my marine blue body colour quite well.
But then again it may look awful
Will know next week for sure.

Cheers/Peter

 

Hightemp tape is a waste of money BTW Flashpoint of paper is 451 degrees. Powder is baked at a max temp of 400 degrees therefore masking tape does the job just fine. Don't coat the gasket surface. Sooner or later you will end up pulling the intake off and having to get the gasket material off. Then you find your self having to grind the powder to make sure you have a good seal with the new intake gasket. As far as coating the underside. Yes coat it. Powder not only looks good but it protects the parts from the elements. Not sure why you would want to coat the inside of the intake. Plug all threaded holes if you are getting a thick coat or having a second coat such as Clear or candy applies or you will have a hard time getting the bolts back in.

 

Thanks for all the good advices,

Yes the intake/head gasket surface will not be powder coated and all the thread holes will be masked before to avoid problems with thick paint.
The rest of underside will be coated though.
I'm really exited to see how this turns out.
Either way I expect it to be a good protective surface, if it comes out not looking very good i just have to pop the hood open at night away from crowds

Cheers/Peter

 

Remove the resonance flap and axle. Figure out a way to protect the bearings from the powder - or you'll spend a lot of time with a dental pick later. Same thing if you are doing the levers from the cable assembly. And also if the latter, protect the axle on the assembly and the ***** of the levers. If you're doing the coolant crossover do not have the gasket mating surfaces coated as you need the metal to metal contact for a ground connection from the sensors.

On S4s and later all the intake gasket mating surfaces were coated from the factory - with whatever it was they used.

 

Hi Dave,

thanks for the heads up on the flappy, it has been removed and i have used bolts washer and nuts to cover the wholes before having the intake shot blasted.
Good point on the coolant crossover, it is also being coated.
Cant remember what we agreed on that but will give the powder coater a call tomorrow and make sure.
Yes my intake had coating every where from factory.
I will not coat the inside again to avoid the risk for the powder coat peeling off.
For pictures on my intake before and after some pressure wash look at this thread, it shows the paint on the gasket surfaces.
(and how easy it came off)
Also note how dark the Magnesium/Alloy looks, after the shoot blasting it looked much brighter almost like Aluminum.

Intake before and after pressure wash

/Peter

 

When we powdercoat we tape everything off usually. If you dont its no big deal an angle grinder with a gasket removing pad will strip the powder coat off in a matter of minutes. Make sure you get your parts powder cleared after the color coating I did a set of S4s lastnight that turned out incredible!

 

Hi Randy,

clear coat is definitively going on as final layer,
Can't wait to se the final result on this.

/Peter